MIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Graduate Theses
  • View Item
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Graduate Theses
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

A constitutive theory for the mechanical response of amorphous metals at high temperatures spanning the glass transition temperature : application to microscale thermoplastic forming of Zr₄₁.₂Ti₁₃.₈Cu₁₂.₅Ni₁₀Be₂₂.₅

Author(s)
Henann, David Lee
Thumbnail
DownloadFull printable version (9.299Mb)
Other Contributors
Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
Advisor
Lallit Anand.
Terms of use
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582
Metadata
Show full item record
Abstract
Bulk metallic glasses (BMGs) are a promising emerging engineering material distinguished by their unique mechanical properties and amorphous microstructure. In recent years, an extremely promising microscale processing method for bulk metallic glasses, called thermoplasticforming has emerged. As with any emerging technology, the scientific basis for this process is at present fragmented and limited. As a result their is no generally agreed upon theory to model the large-deformation, elastic-visco-plastic response of amorphous metals in the temperature range relevant to thermoplastic-forming. What is needed is a unified constitutive framework that is capable of capturing the transition from a elastic-visco-plastic solid-like response below the glass transition to a Newtonian fluid-like response above the glass transition. We have developed a finite-deformation constitutive theory aimed to fill this need. The material parameters appearing in the theory have been determined to reproduce the experimentally measured stress-strain response of Zr₄₁.₂Ti₁₃.₈Cu₁₂.₅Ni₁₀Be₂₂.₅ (Vitreloy-1) in a strain rate range of [10-5, 10-1] s-1, and in a temperature range [593, 683] K, which spans the glass transition temperature [nu]9 = 623K of this material. We have implemented our theory in the finite element program ABAQUS/Explicit. The numerical simulation capability of the theory is demonstrated with simulations of micron-scale hot-embossing processes for the manufacture of micro-patterned surfaces.
Description
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.
 
Includes bibliographical references.
 
Date issued
2008
URI
http://hdl.handle.net/1721.1/44885
Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Publisher
Massachusetts Institute of Technology
Keywords
Mechanical Engineering.

Collections
  • Graduate Theses

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries
PrivacyPermissionsAccessibilityContact us
MIT
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.